Question: The sum of $4$ consecutive even numbers is $84$. What is the second number in this sequence?
Explanation: Call the first number in the sequence $x$ The next even number in the sequence is $x + 2$ The sum of the $4$ consecutive even numbers is: $x+ (x + 2)+ (x + 4)+ (x + 6) = 84$ $4x + 12= 84$ $4x = 72$ $x = 18$ Since $x$ is the first number, $x + 2$ is the second even number. Thus, the second number in the sequence is $20$.